Vibrio cholerae is a marine organism, a symbiont of arthropods, and a pathogen of humans that causes severe and pandemic diarrheal disease. Cholera is acquired by ingestion of contaminated water or food. Because environmental persistence is critical to the epidemic spread of V. cholerae, our laboratory studies the adaptations V. cholerae uses to survive in aquatic environments and in arthropods. The following avenues of investigation are being pursued in our laboratory:

1) Structure and regulation of the Vibrio cholerae biofilm. Adhesion to abiotic surfaces in multicellular structures known as a biofilms is thought to be critical to the environmental survival of V. cholerae. Biofilm formation requires the synthesis of an extracellular matrix that may include exopolysaccharide, proteins, and DNA. In V. cholerae, synthesis of this matrix is very tightly regulated. We are studying signal transduction cascades that regulate synthesis of the V. cholerae biofilm matrix. In addition, we are defining the role that matrix-associated structural proteins play in the architecture of the biofilm.

2) Drosophila melanogaster as a model host for Vibrio cholerae. Arthropods are found with Vibrio species in the environment. We are using the model arthropod Drosophila melanogaster to better understand the association of V. cholerae with arthropods in the environment and to study the interaction of V. cholerae with a model host intestine. This system allows us to apply both host and pathogen genetics to our investigations. We have recently discovered that Vibrio cholerae manipulates intestinal stem cell turnover to decrease host tolerance to this infection. In addition, we are investigating products of bacterial metabolism that modulate host resistance and tolerance.